1. Field of the Invention
The present invention relates to a back-reflection type light diffusing apparatus, and more particularly, to a back-reflection type light diffusing apparatus suitable for use in liquid crystal displays or in seeing through drawings.
2. Description of the Prior Art
Generally, conventional back-reflection type light diffusing apparatuses for use in liquid crystal panel displays are formed of a light guiding plate having one surface which is formed into a light radiating surface and another surface onto which a light reflecting plate is mounted such that light is introduced from one or more positions at the peripheral end of the light guiding plate, and is radiated outwardly through one surface of the light guiding plate over its entire area on being reflected by the light reflecting plate mounted on the other surface thereof.
The conventional back-reflection type light diffusing apparatuses, however, suffer a problem in that more light is radiated in the vicinity of the light emitting portions, and less light is radiated from areas which are distant therefrom which are therefore darker in other words, light cannot be radiated uniformly over the entire area of the light radiating surface.
To obviate this problem, it has been proposed that the peripheral shape of the apparatus body 1 formed by a plate-shaped transparent member be modified, as shown in FIG. 1, in order to maximise the amount of light which passes through the central portion of the body. In the FIG. 1, reference numerals 2 and 3 respectively denote a light reflecting plate mounted around the sides of the body 1 and light sources.
However, such apparatuses have a complicated configuration, and their light sources are only mounted at a limited number of positions. Further, the configuration of such apparatuses has to be determined by a cut-and-try method, and therefore changes depending on the number and positions of the light sources provided. In consequence, much time and labour are required to determine the configuration.